The present invention relates to a method for the investigation of a fuel cell system, said fuel cell system having an anode side to which a fuel is supplied in operation and a cathode side to which an oxidizing agent is supplied in operation and comprising at least one fuel cell, each said fuel cell having a an anode, a cathode and a membrane separating said cathode from said anode, said method being adapted to carry out at least one of the following tests: a) to test whether said fuel cell system is gas-tight at said anode side and/or at said cathode side, b) to test whether a leakage is present between said anode side and said cathode side, c) to test a starting behaviour of said fuel cell system, or d) to test an operation of said fuel cell system at low current yield
Furthermore the present invention relates to an apparatus for the investigation of a fuel cell system for the carrying out of one of the above-named tests.
The testing of a fuel cell system with regard to possible leakages, both when it is first switched on after completion of the fuel cell system and after a repair of a vehicle or of other devices has been carried out into which the fuel cell system is integrated, or with the first time operation of a vehicle or of an apparatus in which the fuel cell system is incorporated, and also during the development of a fuel cell system, requires a hydrogen source and also extensive tests. The testing with hydrogen requires very complicated measures in the testing chambers. For example such testing chambers must be equipped with ventilation systems which operate with a high through-put of air. Various hydrogen detectors and also additional switching off devices are required in order to detect any hydrogen leakages and, in the event a leakage is determined, to switch off the test chamber and also the entire installation present therein. Moreover all electrical systems which are to be found in the testing chambers must be particularly protected against spark formation in order to prevent hydrogen explosions. Only well educated, particularly schooled persons can and may operate in the corresponding test chambers under such conditions.
Even when such complicated measures have already been taken in test chambers during the development of fuel cell systems and vehicles and apparatus which contain such fuel cell systems, the mass manufacture of fuel cell systems or vehicles or other apparatus which contain such fuel cell systems can hardly be carried out with present measures and a particular problem also exists if, for example, a vehicle with a fuel cell system has in future to be repaired in a car repair shop.
For the present leakage testing of fuel cell systems helium is used in place of hydrogen because it has similar diffusion characteristics to the preferred fuel, i.e. hydrogen, is of relatively low viscosity and makes it possible to detect any leakages that are present with helium detectors. For tests which are concerned with the starting or the taking into operation of the fuel cell systems of vehicles or apparatuses with fuel cell systems, it is however necessary to test the system with hydrogen, whereby the above-mentioned complicated measures have to be taken in order to avoid the possibility of an explosive gas mixture in the case of an unintended hydrogen leakage.